Abstract: In order to reduce flight resistance and increase radar scattering, a hybrid method of precision grinding and micro grinding is proposed to fabricate micro-grooves curved surface structures on surface of ceramic flying body. The precision-trued diamond wheel edge is employed to grind ceramic surface into smooth curved surface along CNC curve interpolation paths; the micro-trued diamond wheel with V-tip of 60° is employed to grind micro-grooves structures on ground curved surface along the axial direction of flying body; the wind-driven experiments are performed to investigate the effect of different curved surface structures on air resistance. The experimental results show that micro-grooves structures with the depth of 578-581 μm, angle of 61.56° and tip radius of 48 μm may be fabricated on curved surface of ceramic with the height of 32 mm, diameter of 30 mm and surface roughness of 0.262 μm. The depth error of micro-grooves is only 3 μm. The average form error of curved surface is only 142 μm and it can be controlled below 0.5% by the proposed precision grinding method. Moreover, different grain sizes of diamond wheel and various grinding processes have great influence on surface roughness for curved surface of ceramic. The wind-driven experimental results indicate that micro-grooves structure may reduce axial resistance by 36% and 42% compared to smooth and rough curved surface, respectively. The micro-grooves structure may also reduce lateral resistance by 39% against smooth curved surface. It is confirmed that the regular and controllable micro-groove structures machined on smooth curved surface of ceramic flying body may reduce flying resistance.

Key words: ceramic;micro-grooves structure;precision grinding;resistance